Polymeric bag with elastic drawtape

ABSTRACT

A manufacturing method for producing a plurality of polymeric drawtape bags, the method including: a) dispensing a film of polymeric pliable material; b) producing a web of folded and sealed polymeric panels from the film, the web including a plurality of polymeric bags having a pair of drawtapes added into a pair of hems proximate a bag opening with a series of notches produced near lateral edges of each of the hems exposing the drawtapes with a series of lateral seals applied to the exposed drawtapes within the notches; c) measuring a relative placement of the series of notches with respect to the seals; and d) providing feedback to a notch production system to improve placement of the series of lateral seals of the exposed drawtapes within the notches by accurately locating the series of notches produced along the web.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.61/449,591, filed 4 Mar. 2011, the contents of which are herebyexpressly incorporated in its entirety by reference thereto for allpurposes.

BACKGROUND OF THE INVENTION

The present invention relates generally to polymeric bags, and morespecifically, but not exclusively, to polymeric elastic drawtape trashbags and methods of their manufacture.

Polymeric trash bags are a common household product and have been so formany years. Common trash bags include a variety of polymeric materials,sizes, thicknesses, colors, counts, and closure formats. Polymeric trashbags are used not only for collection, containment, and disposal oftrash and garbage, but also for long term storage of items such asclothing and the like. With the constant growing use of polymeric trashbags, manufacturers are always researching new manufacturing materialsand methods to enhance consumer experience while at the same timeproviding options to generate less waste, enhance sustainability, andimprove profitability.

The closure method of polymeric trash bags differ in design. A commonpolymeric bag design can be as simple two bag panels sealed alongopposing sides creating what is commonly called an ‘open top’ bag. Thisstyle of bag is inserted into a trash container with the upper edges ofthe bag rolled over the container rim to provide a means to hold the bagto the container. When the bag is filled, the bag is removed by pullingthe bag from the trash container, spinning the top of the bag shut, andthen applying a twist-tie (or other closure system) to hold the bagshut. Two specific inherent frustrations apply to this design: (1) Thebags tend to fall into the trash container while filling as the bag doesnot provide a feature to secure the bag to the top of the container; and(2) Consumers have expressed concern that the tie devise sometimesbecome lost thus requiring the consumer to (try to) tie a knot in thebag which can be difficult in the event there is not enough materialremaining in the bag body once filled.

To overcome the ‘open top’ bag closure frustrations, manufacturersdeveloped a polymeric trash bag commonly called “drawtape” and/or“drawstring” trash bags. A typical drawtape (or drawstring) bag featureincludes a pair of polymeric strips enclosed in a formed hem in the topof each bag panel. When polymeric drawtape trash bags are used by aconsumer, the drawtape feature provides a method for removal of thetrash bag from the container as the drawtape acts as a handle forgripping and lifting the bag. Once the bag has been lifted from thecontainer, the polymeric drawtape strips can be tied to each other tosecure the bag shut and then provide a carrying mechanism to transportthe bag to its desired location. Throughout the existence of drawtapestyle polymeric trash bags, this design style has become a commonproduct used in households and business.

Because of the variety of polymeric drawtape trash bag sizes and trashcontainer sizes, a common unsatisfactory experience expressed byconsumers when using a polymeric drawtape trash bag in a container isthe bags do not always remain secured to the top of the containerconsequently when the bag is filled, the bag tends to pull/drop inwardinto the container which then results in trash and garbage notcompletely being captured by the bag thus the trash container is subjectto becoming soiled and unsanitary. When this condition occurs, theconsumer has to reach into the container and through trash to locate thetop of the trash bag—more specifically locate and grip the drawtape pullfeature. When the bag fails to remain in place, the outcome defeats thepurpose of using a bag to provide a barrier between the trash and trashcontainer.

Consumers are always seeking the latest and greatest feature to enhancea product experience. With this in mind, manufacturers began researchingnew materials and methods that offer stretchable drawtape strips intrash bags. The advantage of a stretchable drawtape is simple—when thetop section of a polymeric drawtape trash bag is folded over thecontainer rim, the bag tends to stay in place thus allowing the bagpanels to act as a liner overcoming the need for consumers having toreach into a trash container to reattach the bag to the container rimand having to clean the container interior.

Elastic drawtape polymeric trash bags are manufactured by severalcompanies all of which utilize a variety of manufacturing techniques,methods, materials, and processes. Following are two product descriptionexamples and corresponding consumer experiences.

1. One product design utilizes an elastic polymeric drawtape enclosed inindividual hems along the top of the polymeric trash bag. A dedicatedheat seal attaches the drawtape ends to the bag hem panels on each sideof the bag. The dedicated drawtape seals extend further into the bagbody panel width than the main bag panel seals thus creating a reducedbag opening size (circumference) when measured against the bag panelinterior size (circumference). This reduced opening provides a means tosecure the bag to a container rim. This bag design includes acentralized semicircular cutout in the top of the bag to allow bagclosure when the drawtape strips are pulled through the cutouts. Adescriptive reference for this product is found in US Pub No.2010/0111452-A1 entitled REDUCED OPENING ELASTIC DRAWSTRING BAG filed 30Oct. 2008.

This product design requires the consumer to stretch the upper portionof the bag body hem panels while in the same motion stretching theelastic drawtape strips in order to secure the top of the bag around thecontainer rim. Stretching both the bag body hem panels and elasticdrawtape in one motion requires additional pulling force and strengthfrom the consumer when compared to product #2 described in the nextsection below. Furthermore, when having to pull the drawtape strips froma centralized hole, the experience can lead to cinching/gathering of thebag hem panels upon closure thus making it difficult to fully close thebag. Depending on the consumer, products that require an extra force touse a trash bag may lead to frustration and tendency to purchase otherproducts.

2. One product design utilizes a polymeric drawtape material that is notof an elastic material in design however the drawtape strips have beendesigned in a manner to include looped sections which have an elasticadhesive strip attached to the looped sections. The elastic adhesivestrips are adhered to the polymeric drawtape strips to allow thedrawtape to react in an elastic manner when pulled. There is onedrawtape strip enclosed in each of the two individual bag body hemsalong the top of the polymeric bag. In this design, the bag has a pairof notch cutouts on the top of the bag with one located on each side ofthe bag. The drawtape is sealed to each other (strip 1 to strip 2) whileremaining separate of being sealed to the bag body panels and hemsections. The notch cutouts allow the drawtape to extend outside of thebag body panels. This design requires less force when the drawtape ispulled by the consumer as the consumer only has to stretch the drawtapestrips around the container rim to secure the bag to the container. Adescriptive reference for this product is found in U.S. Pat. No.6,059,458 entitled ELASTIC TOP DRAWTAPE BAG AND METHOD OF MANUFACTURINGTHE SAME filed 5 Feb. 1999.

Depending on the consumer and pulling force exerted during closure, theadhesive strips on the looped drawtape can break free from thenon-elastic drawtape strips thus rendering the stretchable capabilityunusable. Furthermore, it was discovered during visual product analysisthat the notch proximity to the edge of the bag panels varied indimension and the shape was of a rectangular shape vs. a halfsemicircular shape as noted in the aforementioned patent documentdrawings. Depending on the pulling force exerted on the bag duringclosure, the notches tend to enlarge thus creating openings at thedrawtape closure points which could subject the bag contents to pestsand other environmental conditions.

What is needed is an improved design and manufacturing method forpolymeric elastic drawtape bags that addresses the limitations ofexisting bags.

BRIEF SUMMARY OF THE INVENTION

Disclosed is an improved design and manufacturing method for polymericelastic drawtape bags that addresses the limitations of existing bags.The following summary of the invention is provided to facilitate anunderstanding of some of technical features related to polymeric bagsand manufacturing processes thereof, and is not intended to be a fulldescription of the present invention. A full appreciation of the variousaspects of the invention can be gained by taking the entirespecification, claims, drawings, and abstract as a whole.

A drawtape bag includes a body having a pair of pliable opposingpolymeric body panels joined together with a pair of lateral body sealsalong a pair of opposing lateral sides and a bottom bridging and closingthe pair of pliable opposing polymeric body panels producing a polymericbag with an open mouth end at a top end, the body panels each forming ahem extending along the open mouth end, each the hem including a pair oflateral notches at the opposing lateral sides; and a pair of pliablepolymeric elastomeric drawtapes moveably disposed without attachmentwithin the hems, one drawtape within each hem wherein opposing lateralsides of the pair of drawtapes are exposed within the notches and joinedtogether with a pair of lateral drawtape seals to form a single closeddrawtape loop extending around a perimeter of the open mouth end whereinthe single closed drawtape loop is configured to be drawn through one orboth of the pair of lateral notches to close the open mouth end; whereinthe lateral notch has a length in a direction along the hem about 1.625inches or less wherein the body has a width about 24 inches or less anda length about 27 inches or greater.

A method of manufacturing a drawtape bag includes a) directing a pair ofoverlying polymeric film panels in a machine direction wherein the pairof polymeric film panels are joined together at a bottom edge and openat a top edge opposite of the bottom edge to form a single polymericfilm, with the panels being separable from each other along a mouth endformed opposite the bottom edge; b) producing a pair of hems along thetop edges of the film panels of the single polymeric film; c) producingdrawtape notches in each hem of the pair of hems at regular distanceintervals corresponding to a desired width of the drawtape bags; d)adding a pair of pliable polymeric drawtape into the pair of hems, adrawtape disposed into each hem; e) sealing the panels to each otherusing body seal structures generally transverse to the machine directionto create individual drawtape bags; and f) sealing the drawtapes to eachother using drawtape seal structures within the drawtape notches toform, for the drawtape bag, a single closed drawtape loop disposedaround a perimeter of the mouth end.

A manufacturing system for producing polymeric drawtape bags, the systemincluding a plurality of manufacturing stations to dispense polymericpliable material and to produce a web of folded and sealed polymericpanels forming a plurality of polymeric bags having a pair of drawtapesadded into a pair of hems proximate a bag opening with a series ofnotches produced near lateral edges of each of the hems exposing thedrawtapes with a series of lateral seals applied to the exposeddrawtapes within the notches; and a notch registration system, coupledto one or more stations of the plurality of manufacturing stations,measuring a relative placement of the series of notches with respect tothe seals and providing feedback to a notch production system of theplurality of manufacturing stations to improve placement of the seriesof lateral seals of the exposed drawtapes within the notches byaccurately locating the series of notches produced along the web.

A manufacturing method for producing a plurality of polymeric drawtapebags, the method including: a) dispensing a film of polymeric pliablematerial; b) producing a web of folded and sealed polymeric panels fromthe film, the web including a plurality of polymeric bags having a pairof drawtapes added into a pair of hems proximate a bag opening with aseries of notches produced near lateral edges of each of the hemsexposing the drawtapes with a series of lateral seals applied to theexposed drawtapes within the notches; c) measuring a relative placementof the series of notches with respect to the seals; and d) providingfeedback to a notch production system to improve placement of the seriesof lateral seals of the exposed drawtapes within the notches byaccurately locating the series of notches produced along the web.

Although the production lines used to manufacture polymeric drawtapetrash bags utilize industry standard technologies, the process has aninherent variation in the placement of the drawtape notch cutout. Thevariation is partially the result of the pliable characteristic of thefilm and web tension variables. One component of a bag manufacturingline is referred to as “The Dancer” (a downstream component) alsocontributes to notch placement variation as the Dancer tends tooscillate in response to film tension variables thus offsetting thenotch placement. One feature of our invention includes technologies tocontrol and limit the notch placement variations.

Other features, benefits, and advantages of the present invention willbe apparent upon a review of the present disclosure, including thespecification, drawings, and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying figures, in which like reference numerals refer toidentical or functionally-similar elements throughout the separate viewsand which are incorporated in and form a part of the specification,further illustrate the present invention and, together with the detaileddescription of the invention, serve to explain the principles of thepresent invention.

FIG. 1 illustrates a storage system including a receptacle and apolymeric bag sized for use with the receptacle;

FIG. 2 illustrates a front view of a first type of a polymeric drawtapebag;

FIG. 3 illustrates a front view of a second type of a polymeric drawtapebag;

FIG. 4 illustrates an overview of a manufacturing process producing thefirst type of polymeric drawtape bag;

FIG. 5 illustrates an overview of a manufacturing process producing thesecond type of polymeric drawtape bag; and

FIG. 6 illustrates an overview of the control components of themanufacturing process.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the present invention provide an improved design andmanufacturing method for polymeric elastic drawtape bags that addressesthe limitations of existing bags. The following description is presentedto enable one of ordinary skill in the art to make and use the inventionand is provided in the context of a patent application and itsrequirements.

FIG. 1 illustrates a storage system 100 including a receptacle 105 and apolymeric bag 110 sized for use with the receptacle. Storage system 100is ubiquitous and implemented in a wide variety of formats. The presentinvention is most conveniently described in a specific context, but itis understood that it may be adapted for implementation in many othercontexts as well.

The specific preferred context includes bag 110 as a nominally 13 gallon(49.21 liters) drawstring bag with “gripping” technology and having sidehole notch for accessing the drawstring, hereafter referred to as a 13gallon bag. A nominal 13 gallon bag is configured for receptacle 105 asa nominally 13 gallon receptacle, but there is a very wide variation indimensions. For example, even though referred to as a 13 gallonreceptacle, the actual gallon equivalent of receptacle 105 can rangefrom about 9 gallons to about 14 gallons. Receptacle 105 may haverepresentative dimensions ranging from a top rim circumference of about46.5 inches to about 49 inches while a depth dimension varies in a rangeof about 19 inches to about 24 inches. For a limited sampling ofreceptacles, receptacle 105 is, on average, about 12.4 gallons with acircumference of about 48 inches and a depth of about 22 5/9 inches. Anysampling will show variation from these values.

Any manufacturer of bag 110 desirably provides dimensions for bag 110that will provide usefulness to as great a number of people of possible,in as simple and efficient manner as possible. Ultimately for anyparticular implementation of manufacturing for bag 110, specific bagdimensions are chosen in contemplation of a range of useful receptaclesizes. For a “grip” feature, it is contemplated that the circumferenceof the gripper feature of bag 110 will be smaller than the smallestcircumference of the set of receptacles, with elastic “stretching” toprovide the grip. There is a limit to the amount of stretching that canoccur before deformation destroys the elasticity, which defines aneffectively upper bound for the circumference for receptacle 105. For aparticular design of bag 110, the present invention is used to improvethe usefulness to the end-user.

FIG. 2 illustrates a front view of a first type of a polymeric drawtapebag 200. Bag 200 includes a polymeric film 205 with a first fold 210 ata bottom and a pair of lateral edge seals 215 to produce an opening 220at a top. At the top a pair of second folds 225 and a pair of top seals230 create a pair of hems 235 enclosing a pair of drawtapes 240 that aresealed together at a pair of lateral edge seals 245 to produce a singleclosed loop 250 extending through both hems 235. Loop 250 is capturedwithin hems 235, but is otherwise unattached to polymeric film 205 soloop 250 moves independently and freely within hems 235. A set oflateral notches 255 in hems 235 expose lateral edge seals 245 of loop250.

Several important aspects of the present invention relate to thedimensions of the bag, the seals, the notches and the interplay of thesedimensions in the context of use with receptacle 105 shown in FIG. 1. Asnoted above, dimensions of notches 255 affect the size of “holes” in thetop of bag 200 after loop 250 is pulled closed and tied. Notches 255 areused to allow a user to conveniently access loop 250 and to remove bag200 from receptacle 105 so they are necessary but can, when notappropriately addressed, produce such undesirable effects. HeretoforeApplicant is unaware that bag manufacturers have manufactured anapparatus such as bag 200, much less addressed specifically problemsassociated with enlargement of lateral notches 255 in bag 200.

Specifics of bag manufacture vary from one bag format to another. Asnoted, there are different ways of providing a reduced circumferenceopening, not all of which include an independent closed loop drawtapeaccessed by lateral notches with the closed loop drawtape providing thesole gripping function. Important dimensions for bag 200 includeBag_(Width1) and Bag_(Length1) which define the useful capacity of bag200. Lateral side seals 215 each have a width shown as Body_(Seal1)defining a width of the bag opening therebetween. Lateral edge seals 245each have a width shown as Loop_(Seal1) defining a width,Loop_(Length1), therebetween. Notches 255 have a nominal lengthdimension shown as Notch_(Length1). Loop_(Seal1) is greater thanBody_(Seal1) and as explained in more detail herein, Notch_(Length1) isa factor related to Bag_(Width1) and is desirably reduced when possible,while preserving other important characteristics of bag 200.

FIG. 3 illustrates a front view of a second type of polymeric drawtapebag 300. Bag 300 includes a polymeric film 305 with a first fold 310 ata bottom and a pair of lateral edge seals 315 to produce an opening 320at a top. At the top a pair of second folds 325 and a pair of top seals330 create a pair of hems 335 enclosing a pair of drawtapes 340 that aresealed together at a pair of lateral edge seals 345 to produce a singleclosed loop 350 extending through both hems 335. Loop 350 is capturedwithin hems 335, but is otherwise unattached to polymeric film 305 soloop 350 moves independently and freely within hems 335. A set oflateral notches 355 in hems 335 expose lateral edge seals 345 of loop350.

Several important aspects of the present invention relate to thedimensions of the bag, the seals, the notches and the interplay of thesedimensions in the context of use with receptacle 105 shown in FIG. 1. Asnoted above, dimensions of notches 355 affect the size of “holes” in thetop of bag 300 after loop 350 is pulled closed and tied. Notches 355 areused to allow a user to conveniently access loop 350 and to remove bag300 from receptacle 105 so they are necessary but can, when notappropriately addressed, produce such undesirable effects. HeretoforeApplicant is unaware that bag manufacturers have manufactured a drawtapebag such as bag 300, much less addressed specifically problemsassociated with enlargement of lateral notches 355 in bag 300.

Specifics of bag manufacture vary from one bag format to another. Asnoted, there are different ways of providing a reduced circumferenceopening, not all of which include an independent closed loop drawtapeaccessed by lateral notches with the closed loop drawtape providing thesole gripping function. Important dimensions for bag 300 includeBag_(Width2) and Bag_(Length2) which define the useful capacity of bag300. Lateral side seals 315 each have a width shown as Body_(Seal2)defining a width of the bag opening therebetween. Lateral edge seals 245each have a width shown as Loop_(Seal2) defining a width,Loop_(Length2), therebetween. Notches 255 have a nominal lengthdimension shown as Notch_(Length2). Loop_(Seal2) is equal toBody_(Seal2) with Bag_(Width2) less than Bag_(Width1) and Bag_(Length2)greater than Bag_(Length1) (to make the capacity of the bag 300essentially the same as bag 200), Notch_(Length2) is less thanNotch_(Length1), and as explained in more detail herein, Notch_(Length2)is a factor related to Bag_(Width2) and is desirably reduced whenpossible, while preserving other important characteristics of bag 300.

For example, Notch_(Length1) is at least about 1.625 inches (and may beincreased in some implementations if variation in notch cutting riskshaving a lateral edge seal 345 sealed to hems 335). Loop_(Seal1) isabout 0.625 inches greater than Body_(Seal1). For other bag designshaving lateral cutouts accessing an enclosed elastic-type drawstring,notch lengths are significantly larger and can be about 2.25 inches toabout 2.5 inches. As further discussed below, use of a novelmanufacturing process enables the notch length to be reduced. Forexample, Notch_(Length2) is about 1 inch, with Loop_(Seal2) about equalto Body_(Seal2).

FIG. 4 illustrates an overview of a manufacturing process 400 producingthe first type of polymeric drawtape bag 200 shown in FIG. 2. Process400 includes three manufacturing stations, a dispensing station 405, afirst forming station 410, and a second forming station 415. Station 405holds a roll 420 of polymeric pliable material (aka polymeric film) 425.Roll 420 is manufactured in a blown film extrusion process in the shapeof a tube that is flattened into a web format, then cut on one side andthen wound into a finished roll 420. Film 425 drawn off roll 420includes a fold 430 at a bottom edge while a top edge is open, whichcreates a front panel (shown) and a back panel (not shown). Station 405delivers film 425 to station 410 and then to station 415 for furtherprocessing.

Station 410 pulls film 425 over a set of folding plates where a sectionof both the front and back film panels at the top end are each foldedback over a pair of elastomeric (e.g., formed of a polymeric material tobe elastic for expanding, gripping receptacle openings to hold bagupright) drawtapes 432. A top seal 435 is applied to both the front andthe back film panels to form a pair of hems 440 and the bag openingtherebetween (only the front drawtape 432, seal 435, and hem 440 areshown for clarity). Specifically, a cutter (aka—Servo Cutter or thelike) periodically cuts a pair of notches 445, one notch 445 into eachpanel, to expose periodic openings in the top edge. Film 425 continuesdownstream over a set of folding bars where the individual front andback bag are separated and hem 440 is then formed respectively in eachpanel. At this point, a single strip of polymeric elastic drawtape 432is inserted into each hem 440 (a first strip inserted into a front hem440 and at the same time a second strip inserted into a back hem 440).Film 425 continues downstream where the respective top seals 435 areapplied to both the front and back panels, thus creating hems 440, onein each panel, with each hem 440 enclosing one polymeric elasticdrawtape 432.

Film 425 continues from station 410 in this format downstream intostation 415 for further processing. Film 425 travels through a webtensioning device (aka—a Dancer), and continues downstream around asealing drum where periodic bag panel seals 450 and drawtape seals 455are made. Seals 450 are made from primary seal bar mechanisms secured inthe sealing drum. Seals 450 are made from seal bars that are secured tothe primary seal bars however the sealing variables are controlledseparate of the primary seal bar. Film 425 continues over a series offolding bars for folding the sealed film into a folded web format.

The folded web then travels through a perforation knife cutting stationwhere periodic perforations 460 are made to folded web which provides amechanism to separate the sealed web format into individual bags in adownstream machine (e.g., a folder, winder, or the like—not shown). Bag200 may be thus made by process 400 and provides good results for arange of products. A controller 465 using a feedback system 470 isoptional in process 400 for notch placement, but its use as furtherdescribed herein could improve notch placement and permit narrowernotches to be employed and thereby improving bag 200 by reducing thenotch hole enlargement issue described herein.

Process 400 includes a considerable length of film 425 throughout themanufacturing line. For example, a distance between the Servo Cutter atstation 410 and a web perforation device at a downstream end of station415 is about fifty feet. This equates to about 25 bags thus anyvariation in a tension of film 425 tension typically results inoscillations in the Dancer which in turn creates an expansion orretraction of the web path in the machine direction. These oscillationscause the notch cutout placement to move proportionally to the webexpansion/retraction. In the event the notch cutout 445 moves upstreamor downstream as the result of the web movement, notch 445 may bepositioned in the immediate area of the drawtape seal 450 thus becomingsealed to either end of hem 440 thus rendering the elasticcharacteristic of drawtape 432 to not function as designed. In order toprovide a means of compensation for the web expansion/retraction and toensure a precise placement of notch 445 and its registration to the bagpanel side seals 450 and drawtape seal 450, controller 465 and feedbacksystem 470 are used and the tighter these registration requirements(e.g., smaller notches), the more useful is controller 465 and feedbacksystem 470. Thus, for process 500 described below in FIG. 5 forproduction of bag 300, the controller and feedback system are desirablyincluded.

FIG. 5 illustrates an overview of manufacturing process 500 producingthe second type of polymeric drawtape bag 300 shown in FIG. 3. Asfurther described below, process 500 is similar to process 400 exceptthat bag 300 is produced instead of bag 200. Thus process 500 makes abag that is narrower, longer, and has a smaller notch, primarily bycontrolling registration better using a controller and a feedbacksystem. Process 500 includes three manufacturing stations, a dispensingstation 505, a first forming station 510, and a second forming station515. Station 505 holds a roll 520 of polymeric pliable material (akapolymeric film) 525. Roll 520 is manufactured in a blown film extrusionprocess in the shape of a tube that is flattened into a web format, thencut on one side and then wound into a finished roll 520. Film 525 drawnoff roll 520 includes a fold 530 at a bottom edge while a top edge isopen, which creates a front panel (shown) and a back panel (not shown).Station 505 delivers film 525 to station 510 and then to station 515 forfurther processing.

Station 510 pulls film 525 over a set of folding plates where a sectionof both the front and back film panels at the top end are each foldedback over a pair of drawtapes 532. A top seal 535 applied to both thefront and back film panels to form a pair of hems 540 and the bagopening therebetween (only the front drawtape 532, seal 535, and hem 540are shown for clarity). Specifically, a cutter (aka—Servo Cutter or thelike) periodically cuts a pair of notches 545, one notch 545 into eachpanel, to expose periodic openings in the top edge. Film 525 continuesdownstream over a set of folding bars where the individual front andback bag are separated and hem 540 is then formed respectively in eachpanel. At this point, a single strip of polymeric elastic drawtape 532is inserted into each hem 540 (a first strip inserted into a front hem540 and at the same time a second strip inserted into a back hem 540).Film 525 continues downstream where the respective top seals 535 areapplied to both the front and back panels, thus creating hems 540, onein each panel, with each hem 540 enclosing one polymeric elasticdrawtape 532.

Film 525 continues from station 510 in this format downstream intostation 515 for further processing. Film 525 travels through a webtensioning device (aka—a Dancer), and continues downstream around asealing drum where periodic bag panel seals 550 and drawtape seals 555are made. Seals 550 are made from primary seal bar mechanisms secured inthe sealing drum. Seals 550 are made from seal bars that are secured tothe primary seal bars however the sealing variables are controlledseparate of the primary seal bar. Film 525 continues over a series offolding bars for folding the sealed film into a folded web format.

The folded web then travels through a perforation knife cutting stationwhere periodic perforations 560 are made to folded web which provides amechanism to separate the sealed web format into individual bags in adownstream machine (e.g., a folder, winder, or the like—not shown). Bag300 may be thus made by process 500 and provides good results for arange of products just as is true for bag 200, with bag 300 providing asmaller notch-induced hole. A controller 565 using a feedback system 570is preferred in process 500 for accurate notch placement to reduce notchlength.

FIG. 6 illustrates an overview of a notch registration control system600 useful in the manufacturing processes described herein, specificallyas the “optional” components in process 400 and the “preferred”components in process 500. Of course a control system exists forprocesses 400 and 500 and the notch registration control system is anadd-on (or integrated) function for a preferred system of achieving agoal of reduced notch length for any bag format using a manufacturingprocess generally similar to those described herein. Thus not allcontrol and feedback systems and components used in processes 400 and500 are described herein.

Control system 600 includes components that are preferably integratedinto station 510 (and optionally station 410) and station 515 (andoptionally into station 415) as shown. Components of control system 600included in station 510 are an operator programmable interface 605, aweb encoder 610, a servo controller 615, and a servo cutter motor 620.Interface 605 is used for the initial registration set point value asentered by an operator. Web encoder 610 generates a web speed feedbacksignal used at station 515. Servo controller 615 initiates a controlsequencing of servo cutter motor 620. Servo cutter motor 620 actuates anotch cutter through the polymeric film as described herein.

Components of control system 600 included in station 515 include amotion controller 625, a dancer and roller assembly 630, and a danceroscillation position feedback device 635. Dancer and roller assembly 630provide real-time feedback of motion of the film as it travels throughthe stations of process 500. Rotary oscillations of dancer and rollerassembly 630 are converted into linear oscillations by danceroscillation position feedback device 635 and then into a danceroscillation signal. Motion controller 625 is a central coordinationpoint for process and feedback communication regarding notchregistration. Motion controller 625 receives the web speed signal fromweb encoder 610 and the dancer oscillation signal from danceroscillation position feedback device 635. Additionally, there is a notchregistration feedback signal indicating current downstream notchregistration as described below.

The notch registration feedback signal is obtained from capturing aparameter of the film as it relates to where the system is placing thenotch in relation to the body and loop seals. Preferably system 600 usesa vision capture system at a vision capture point between two bagsdownstream of station 515. Preferably this vision capture point is adistance between a bag perforation 560 and a vertical trailing edge 640of each notch cutout 545. This vision capture point is the same point oneach bag during line operation.

System 600 includes, for a vision system, an imager 645 (e.g., feedbacksystem 570) and a vision feedback processor 650 (e.g., controller 565).Imager 645 includes a digital capture imaging sensor that inspects aplacement of edge 640 with respect to perforation 560. Imager 645 worksin cooperation with feedback processor 650 to send a notch registrationfeedback signal to motion controller 625 so motion controller 625 canset precise registration of notch 545.

Description of Systems Control:

Upon start-up of the manufacturing line, an initial notch registrationoffset is set by a programmed value entered into interface 605 by anoperator as determined by a visual measurement of a placement of notch545 and its relation to perforation 560. During line operation, atrigger signal is generated from the bag machine perforation drum and isrelayed to motion controller 625. Motion controller 625 uses feedbackfrom three interface sources: web encoder 610 that measures web speed,feedback processor 650 providing the notch registration feedback signalbased on a pixel count of stored images against a live image capturefrom imager 645 during operation, and dancer oscillation positionfeedback device 635. As the line continues to run, motion controller 625calculates notch registration adjustments based on real time feedbackfrom the web encoder, vision and dancer feedback systems. Motioncontroller 625 maintains registration by outputting a signal to servocontroller 615 at every sequence of the perforation drum.

The improved manufacturing process can be implemented under programcontrol of a plurality of machine code instructions accessed from amemory and executed by a controller or processor. Some or all of theinventive aspects of certain ones of the embodiments of the presentinvention may be implemented in such non-transitory program instructionsstored in a memory.

As noted herein, the system and process are most preferably implementedin a polymeric bag used for collection and storage of materials. Thesystem and methods above has been described in general terms as an aidto understanding details of preferred embodiments of the presentinvention. Other preferred embodiments of the present include thedescribed application for improved polymeric trash bags. In thedescription herein, numerous specific details are provided, such asexamples of components and/or methods, to provide a thoroughunderstanding of embodiments of the present invention. The preferredembodiments include specific physical processing devices and steps, suchas cutters for notches and inserters for placing drawtapes into formedhems. The preferred invention encompasses other devices and methods forproducing notches, e.g., punches, lasers, and other processing equipmentand methods, to yield the desired structures.

One skilled in the relevant art will recognize, however, that anembodiment of the invention can be practiced without one or more of thespecific details, or with other apparatus, systems, assemblies, methods,components, materials, parts, and/or the like. In other instances,well-known structures, materials, or operations are not specificallyshown or described in detail to avoid obscuring aspects of embodimentsof the present invention.

Reference throughout this specification to “one embodiment”, “anembodiment”, or “a specific embodiment” means that a particular feature,structure, or characteristic described in connection with the embodimentis included in at least one embodiment of the present invention and notnecessarily in all embodiments. Thus, respective appearances of thephrases “in one embodiment”, “in an embodiment”, or “in a specificembodiment” in various places throughout this specification are notnecessarily referring to the same embodiment. Furthermore, theparticular features, structures, or characteristics of any specificembodiment of the present invention may be combined in any suitablemanner with one or more other embodiments. It is to be understood thatother variations and modifications of the embodiments of the presentinvention described and illustrated herein are possible in light of theteachings herein and are to be considered as part of the spirit andscope of the present invention.

It will also be appreciated that one or more of the elements depicted inthe drawings/figures can also be implemented in a more separated orintegrated manner, or even removed or rendered as inoperable in certaincases, as is useful in accordance with a particular application.

Additionally, any signal arrows in the drawings/Figures should beconsidered only as exemplary, and not limiting, unless otherwisespecifically noted. Furthermore, the term “or” as used herein isgenerally intended to mean “and/or” unless otherwise indicated.Combinations of components or steps will also be considered as beingnoted, where terminology is foreseen as rendering the ability toseparate or combine is unclear.

As used in the description herein and throughout the claims that follow,“a”, “an”, and “the” includes plural references unless the contextclearly dictates otherwise. Also, as used in the description herein andthroughout the claims that follow, the meaning of “in” includes “in” and“on” unless the context clearly dictates otherwise.

The foregoing description of illustrated embodiments of the presentinvention, including what is described in the Abstract, is not intendedto be exhaustive or to limit the invention to the precise formsdisclosed herein. While specific embodiments of, and examples for, theinvention are described herein for illustrative purposes only, variousequivalent modifications are possible within the spirit and scope of thepresent invention, as those skilled in the relevant art will recognizeand appreciate. As indicated, these modifications may be made to thepresent invention in light of the foregoing description of illustratedembodiments of the present invention and are to be included within thespirit and scope of the present invention.

Thus, while the present invention has been described herein withreference to particular embodiments thereof, a latitude of modification,various changes and substitutions are intended in the foregoingdisclosures, and it will be appreciated that in some instances somefeatures of embodiments of the invention will be employed without acorresponding use of other features without departing from the scope andspirit of the invention as set forth. Therefore, many modifications maybe made to adapt a particular situation or material to the essentialscope and spirit of the present invention. It is intended that theinvention not be limited to the particular terms used in followingclaims and/or to the particular embodiment disclosed as the best modecontemplated for carrying out this invention, but that the inventionwill include any and all embodiments and equivalents falling within thescope of the appended claims. Thus, the scope of the invention is to bedetermined solely by the appended claims.

1. A drawtape bag comprising: a body including a pair of pliableopposing polymeric body panels joined together with a pair of lateralbody seals along a pair of opposing lateral sides and a bottom bridgingand closing said pair of pliable opposing polymeric body panelsproducing a polymeric bag with an open mouth end at a top end, said bodypanels each forming a hem extending along said open mouth end, each saidhem including a pair of lateral notches at said opposing lateral sides;and a pair of pliable polymeric elastomeric drawtapes moveably disposedwithout attachment within said hems, one drawtape within each hemwherein opposing lateral sides of said pair of drawtapes are exposedwithin said notches and joined together with a pair of lateral drawtapeseals to form a single closed drawtape loop extending around a perimeterof said open mouth end wherein said single closed drawtape loop isconfigured to be drawn through one or both of said pair of lateralnotches to close said open mouth end; wherein said lateral notch has alength in a direction along said hem about 1.625 inches or less whereinsaid body has a width about 24 inches or less and a length about 27inches or greater.
 2. The drawtape bag of claim 1 wherein a drawtapeseal width of said lateral drawtape seal is greater than a lateral bodyseal width of said lateral body seal.
 3. The drawtape bag of claim 2wherein said drawtape seal width, as measured as a distance extendinginto said body from a lateral edge, is at least 0.5 inches greater thansaid lateral body seal width.
 4. A drawtape bag comprising: a bodyincluding a pair of pliable opposing polymeric body panels joinedtogether with a pair of lateral body seals along a pair of opposinglateral sides and a bottom bridging and closing said pair of pliableopposing polymeric body panels producing a polymeric bag with an openmouth end at a top end, said body panels each forming a hem extendingalong said open mouth end, each said hem including a pair of lateralnotches at said opposing lateral sides; and a pair of pliable polymericelastomeric drawtapes moveably disposed without attachment within saidhems, one drawtape within each hem wherein opposing lateral sides ofsaid pair of drawtapes are exposed within said notches and joinedtogether with a pair of lateral drawtape seals to form a single closeddrawtape loop extending around a perimeter of said open mouth endwherein said single closed drawtape loop is configured to be drawnthrough one or both of said pair of lateral notches to close said openmouth end; wherein said lateral notch has a length in a direction alongsaid hem about 1 inch or less wherein said body has a width about 23inches or less and a length about 28.25 inches or greater.
 5. Thedrawtape bag of claim 4 wherein a lateral drawtape seal width of saidlateral drawtape seal is about equal to a lateral body seal width ofsaid lateral body seal.
 6. The drawtape bag of claim 5 wherein saidseals are about 0.125 inches wide.
 7. A method of manufacturing adrawtape bag, comprising the steps of: a) directing a pair of overlyingpolymeric film panels in a machine direction wherein said pair ofpolymeric film panels are joined together at a bottom edge and open at atop edge opposite of said bottom edge to form a single polymeric film,with the panels being separable from each other along a mouth end formedopposite the bottom edge; b) producing a pair of hems along said topedges of said film panels of said single polymeric film; c) producingdrawtape notches in each hem of said pair of hems at regular distanceintervals corresponding to a desired width of the drawtape bags; d)adding a pair of pliable polymeric drawtape into said pair of hems, adrawtape disposed into each hem; e) sealing said panels to each otherusing body seal structures generally transverse to the machine directionto create individual drawtape bags; and f) sealing said drawtapes toeach other using drawtape seal structures within said drawtape notchesto form, for the drawtape bag, a single closed drawtape loop disposedaround a perimeter of said mouth end.
 8. The method of claim 7 whereinsaid drawtape seal structures are wider than said body seal structures.9. The method of claim 7 wherein said drawtape seal structures are aboutequal to said body seal structures.
 10. The method of claim 7 furthercomprising the steps of: g) perforating each said seal structuregenerally transverse to said machine direction to define the drawtapebag between successive perforations.
 11. The method of claim 10 furthercomprising the steps of: i) imaging said successive perforations inrelation to a trailing edge of associated successive drawtape notches toprovide a series of notch registration signals; and j) adjusting saidforming step c) responsive to said series of notch registration signals.12. A manufacturing system for producing polymeric drawtape bags, thesystem comprising: a plurality of manufacturing stations to dispensepolymeric pliable material and to produce a web of folded and sealedpolymeric panels forming a plurality of polymeric bags having a pair ofdrawtapes added into a pair of hems proximate a bag opening with aseries of notches produced near lateral edges of each of said hemsexposing said drawtapes with a series of lateral seals applied to saidexposed drawtapes within said notches; and a notch registration system,coupled to one or more stations of said plurality of manufacturingstations, measuring a relative placement of said series of notches withrespect to said seals and providing feedback to a notch productionsystem of said plurality of manufacturing stations to improve placementof said series of lateral seals of said exposed drawtapes within saidnotches by accurately locating said series of notches produced alongsaid web.
 13. A manufacturing method for producing a plurality ofpolymeric drawtape bags, the method comprising the steps of: a)dispensing a film of polymeric pliable material; b) producing a web offolded and sealed polymeric panels from said film, said web including aplurality of polymeric bags having a pair of drawtapes added into a pairof hems proximate a bag opening with a series of notches produced nearlateral edges of each of said hems exposing said drawtapes with a seriesof lateral seals applied to said exposed drawtapes within said notches;c) measuring a relative placement of said series of notches with respectto said seals; and d) providing feedback to a notch production system toimprove placement of said series of lateral seals of said exposeddrawtapes within said notches by accurately locating said series ofnotches produced along said web.